Skipping it will spare him the spectacle of being hounded by human rights protesters in the US, and Mr Trump from more criticism for hosting a leader being accused before an international court of "mass murder".

Human rights groups say more than 7,000 suspected drug dealers and users have been killed by police and vigilantes in Mr Duterte's narcotics crackdown.

"By welcoming Mr Duterte to meet him in the White House, Mr Trump risks giving Mr Duterte's actions - and his brutal human rights violations - an American stamp of approval," Senator Chris Coons, a member of the Senate Foreign Relations Committee, said in a statement.

Another member of the committee, Senator Christopher Murphy, said on Twitter: "We are watching in real time as the American human rights bully pulpit disintegrates into ash."

Experts say Mr Duterte may still visit the US. He just does not want to come across as too eager to do so because of what he has said in the past.

He once declared he would not go to the US, "not in this lifetime" and recalled telling an American diplomat: "Even if you grant me a multiple lifetime visa and give me US$50,000 (S$70,000), I will not go there any more."

That sentiment comes from his early dalliances with communists, long-held grudges at the US over what he still sees as personal insults, including being denied a US visa once, and relentless criticisms by Washington of the extrajudicial killings.

Mr Duterte also has to assure his new friends in Beijing that a US visit will not, in any way, diminish his fondness for China.

He has already devoted a fair amount of diplomatic capital to warm his nation's once-frosty relations with China, and Beijing has rewarded him with billions of dollars worth of investments and grants, and unconditional support for his anti-crime drive.

But a US visit may be good for Mr Duterte, said analysts.

"It would be good to have a broader relationship with key allies and partners; to strengthen relations with new friends like China; but also keep old partnerships not just with the US but also with Australia, Japan and the rest of Asean," said Mr Dindo Manhit, president of Manila-based think-tank Stratbase ADRi.

"It is not good that he may be too centred on this relationship with China, which continues to be our greatest security threat."